The invention relates to a spacer for insulating glass panes, including a profile body made from a plastics material which has a substantially rectangular cross section having first and second mutually parallel side walls and an inner wall that extends between the first and the second side wall, and an outer wall that extends between the first and the second side wall, substantially parallel to the inner wall, and with the profile body forms a closed hollow profile.
Many different spacers of this kind are known in the prior art and are used in the context of improving heat insulation in insulating glass panes of windows and doors, facade elements and the like, in place of the previously usual metal spacers, to keep two glass panes at a spacing from one another. To this end, endless or rod-shaped material is bent, typically by cold forming, to give a frame that corresponds to the size of the window, door, etc.
At the same time, the spacers have by means of their hollow profile the task of receiving desiccants such that the intermediate space between the panes that is formed in the insulating glass pane remains substantially free of water vapour and so condensation effects can be avoided in the event of large differences between the internal and external temperature.
German utility model DE 93 03 795 U1 and European patent application EP 0 601 488 A2 each disclose plastics spacers for insulating glass panes in which metal reinforcing elements are embedded in the plastics material, wherein metal foils are embedded in the side walls and the outer wall and metal foils and/or filamentary reinforcing elements are embedded in the inner wall. The term “filamentary reinforcing elements” is understood to mean reinforcing elements in the form of wire or tubes, and these may in particular also take the form of a cord formed of strands, or of a helical wire, for example of steel or aluminium. Here, the dimensioning of the reinforcing elements arranged in the inner wall is such that this wall is stabilised and strengthened, with the result that it is not to be deformed by thermal expansion or solar irradiation.
In contrast, WO 1999/041481 A1 discloses a spacer for insulating glass panes in which reinforcing elements, either in the form of wires or flat or angled profiles, are arranged in particular in the side walls and corner regions of the substantially rectangular profile, and by means of these reinforcing elements deformability of the spacer profile is sought, similar to that known from the metal spacers, such that conventional bending equipment may be used for cold bending the plastics spacer profiles.
WO 2011/091986 A2 uses large-surface metal materials, as already known from EP 0 601 488 A2, for reinforcing the plastics hollow profiles, wherein the reinforcing elements are arranged on the outside of the outer wall and the side walls, while they are embedded in the plastics material in the inner wall or are mounted on the surface of the inner wall by means of an adhesion promoter.